CEO Bill Johnson made the announcement at a Thursday board meeting in Oxford, Miss., citing stricter environmental regulations and flat demand for power.

Peter Mahurin, a board member from Bowling Green, Ky., said the decision was "a personal nightmare," but acknowledged that he believes it is "in the best interest of TVA's customers."

Right now, coal accounts for 38 percent of TVA's generating capacity.

According to The Associated Press:

"Senate Republican Leader Mitch McConnell met with Johnson last month to seek continued operation of all three coal-burning units at Paradise Fossil Plant in Drakesboro, Ky. The board had previously approved upgrading the two oldest units with environmental controls. But on Thursday, Chief Operating Officer Chip Pardee recommended building a gas plant there instead. ...

"The board also voted to close all five units at the [1,184-megawatt] Colbert plant in northwest Alabama and one of two remaining units that had not been marked for closure at the Widows Creek plant in northeast Alabama."

KnoxvilleBiz.com says the TVA "has shut down a half-dozen units in the past two years ... and expects to generate more power from nuclear plants than coal within the next three years."

AL.com reported in July that national environmental groups were asking the Environmental Protection Agency to impose new regulations on some TVA plants in Alabama that were "polluting rivers and lakes with toxins found in ash and sludge."